1. Field of the Invention
The present invention relates to an exhauster for a motorcycle that has a first exhaust pipe connected with an engine, an exhaust chamber connected with the first exhaust pipe, and a second exhaust pipe connected with the exhaust chamber.
2. Description of Related Art
An exhauster for a motorcycle having a V-type four-cylinder engine in related art includes left and right front exhaust pipes connected with left and right front cylinders, left and right rear exhaust pipes connected with left and right rear cylinders, an expansion chamber connected with these four exhaust pipes, and a pair of left and right mufflers connected with the expansion chamber (for example, see JP-B-7-111139).
According to JP-B-7-111139, a pair of left and right exhaust control valves (passage area control mechanism) for varying passage area is provided at downstream end openings of the left front and rear exhaust pipes and at downstream end openings of the right front and rear exhaust pipes inside the expansion chamber so as to improve engine output.
An exhauster structure in the related art containing a pair of passage area control mechanisms on both the left and right sides within the expansion chamber has disadvantages in an increased number of components and increased costs.